(CNN)–The mother of a gay detective has been booted from the Tennessee church she attended for decades.

Elders at Ridgedale Church of Christ told Linda Cooper and two relatives that their public support for Kat Cooper, Linda Cooper's gay daughter, went against the church's teachings, local media reported. In a private meeting, reports say, Linda Cooper was given a choice: publicly atone for their transgressions or leave the church.

Linda left the church.

Kat Cooper is a detective with the Collegedale Police Department. This month, she fought successfully for health benefits for her same-sex spouse, Krista, from the town.

The Board of Commissioners passed a resolution allowing for same-sex partner benefits, becoming the first city in Tennessee to do so.

Along the way, the mother publicly supported her daughter. That support appears to have led to a rift with her church.

"My mother was up here and she sat beside me. That's it," Kat Cooper told the Times Free Press of Chattanooga. "Literally, they're exiling members for unconditionally loving their children - and even extended family members."

"Her answer to them ... is that she had committed no sin in her mind. Loving her daughter and supporting her family was not a sin," Kat Cooper's father, Hunt Cooper, told CNN affiliate WTVC. "There was nothing to repent about. They certainly couldn't judge her on that because that was between her and her God, and it was not their place to judge her for that."

"The sin would be endorsing that lifestyle," Ken Willis, a minister at Ridgedale Church of Christ, told to the Times Free Press. "The Bible speaks very plainly about that."

The news enflamed the passions of critics and supporters of the church's action.

A phony Facebook page for the church was created by one critic, who posted glib messages affirming same-sex marriage shortly after the controversy went viral. "There's nothing about girl on girl in Leviticus," one post reads.

Mary Sturdibint, a Collegedale resident, told WTVC, "I don't think they should be kicked out of church. If you're going to kick out someone, it needs to be the two that are same-sex that's married. I do believe in that."

Willis declined an on-camera interview with WTVC but released a written statement.

"This is an in-church private issue. Because emotions are so inflamed at this point, I choose not to comment any further," it read.

"The church is overseen by elders. I am a minister, not a pastor and therefore, do not have the authority to speak further on this. The news is getting mixed reviews."

Multiple calls to the church and the Coopers by CNN were not returned.

Church of Christ structure

What happens next for the small suburban church remains unclear.

There is no denomination to hand down an edict praising or condemning the local church's decision.

Churches of Christ are a loosely joined group of independent churches that are autonomous by design. There is no denominational oversight, formal structure or even a denomination headquarters.

Local churches are governed by appointed elders in a structure the church traces to the early followers of Jesus described in the New Testament, said Ronald Highfield, a professor of religion at Pepperdine University.

"They're organized in congregations with their own local leadership so that no other congregation, no set of congregations, no convention can exercise any ecclesiastical discipline over another congregation," said Highfield, who is also an elder in his local Church of Christ congregation.

While there are no documents or position papers by the church on the issue of homosexuality and how members ought to interact with lesbian, gay, bisexual or transgender family members, he said that on the issue of sexual orientation, churches in the denomination fall on a spectrum from progressive to conservative.

Most churches, Highfield said, hold a traditional Christian belief that sex is to be reserved for married men and women and that sex outside of that marriage arrangement is wrong, regardless of what the church believes about sexual orientation.

"There is an implicit covenant when you're a member of a congregation to adhere to the scriptures and the authority," he said.

So, he said, supporting a view that could be seen as undermining the teaching of the church could be grounds for excommunication.

Highfield was unfamiliar with this particular congregation until the story broke and said as for its decision, "whether it's just or fair, I'm not going to make a judgment."

Not a new issue

For decades, churches have wrestled with the issue of homosexuality, leading to splits and schisms of individual congregations and entire churches.

While churches that have formally shifted their policies on same-sex marriage are in the minority, Americans' opinion of such marriage has shifted significantly from opposition to support.

A CNN/ORC poll conducted in June, when the Supreme Court was deciding the fate of the Defense of Marriage Act and the validity of a California law banning same-sex marriage, 55% of Americans said marriages between gay or lesbian couples should be recognized as valid. That marked an 11-point swing from 2008, when 44% of Americans said the unions should be legal.

The public outcry about the exile of the parents of a gay adult child from this Tennessee congregation seems to mirror this shift in public opinion.

Some pollsters and commentators have pointed to tension about same-sex marriage as a reason for an exodus from churches, particularly among young people.

Pew has also noted that at the same time younger Americans are leaving churches, older Americans are returning in a pattern that matches historical trends that have shown people become more religious as they get older.

Because there is no central office for Churches of Christ, reliable numbers on membership are difficult to come by.*

When the Ridgedale congregation next updates its membership rolls, it will be crossing out the Coopers. The family told the local newspaper they were devastated to leave a church where they had been active for 60 years.

For now, both the Coopers and their former church are standing by their own convictions, and after six decades of traveling together, they are heading in different directions.

The CNN Belief Blog covers the faith angles of the day's biggest stories, from breaking news to politics to entertainment, fostering a global conversation about the role of religion and belief in readers' lives. It's edited by CNN's Daniel Burke with contributions from Eric Marrapodi and CNN's worldwide news gathering team.